What is a screen Eavesdrop ?

TEMPEST SDR (Software-Defined Radio) refers to a type of radio system that is designed to capture and analyze electromagnetic emissions, including radio signals, that are unintentionally generated by electronic devices, such as computers, monitors, keyboards, or other equipment.

The term "TEMPEST" originally referred to a U.S. government codename for a program that studied and developed methods for protecting against such unintentional electromagnetic emissions, which can potentially leak information and be intercepted by unauthorized parties.

SDR are a precious tool for passive eavesdrop. By listening to the electromagnetic radiation of an electronic device, one can find hidden information passively (or actively) emitted. If you are interest in this theme, you can have a look on a survey we made on this precise topic.

Screen are connected to devices by cables, often HDMI or VGA. This can lead to an unwanted emission of the image signal through electromagnetic wave. A passive listener can retrieve the image signal without be in the same room of the targeted PC !

A simple Video example done without any modification of the eavesdropped PC!